I am not able to understand the meaning of 'mid-aughts' below. I checked the dictionary, but the meaning is given as 'ought' or 'nothing, zero'. That does not seem to fit here.
The following is from an article in The New Yorker about Wall Street Crime, called 'A Dirty Business' .
At Galleonís daily 8:30 A.M. meeting, he always had more information than his employees and didnít hesitate to let them know it. By the mid-aughts, hedge funds accounted for nearly half of all stock trades, and there was ferocious competition for wealthy investors and the business of investment banks. Thank you